1. Field of the Invention
The present invention relates to apparatus and a method for extinguishing oil well fires. More particularly, a source of cryogenic, inflammable material is brought into close proximity to the well and released. The flame is asphyxiated, and sufficient heat energy is absorbed so that immediate autoignition is prevented.
2. Description of the Prior Art
Numerous innovations for methods and apparatus for exhausting oil well fires have been provided in the prior art. A recent example of the need for an apparatus for extinguishing oil well fires arose during the Persian Gulf War of 1991. During this episode, as many as seven hundred oil wells in Kuwait were intentionally set on fire. These wells resisted the efforts of specialists in getting them under control. The usual difficulties in controlling oil well fires were compounded by environmental conditions inherent in the desert area of Kuwait. One of the environmental conditions which complicated the controlling of the oil well fires is the limited water supply of the area. A second complication resulting specifically from the war in the Persian Gulf is that experts were only allowed limited use of heavy machinery due to the presence of land mines in the area.
Burning oil wells, generally, if out of control, can create serious damage to land, property, water supplies, and the air. The burning oil wells of Kuwait are thought to have affected the environment.
On other occasions, oil wells have caught on fire unintentionally. Regardless of the cause of the fire, a need remains for an apparatus for extinguishing oil well fires. The ideal apparatus for extinguishing oil well fires is very safe, quick, and efficient to use in situations when there is limited water supply or limited use of heavy machinery or in the event that both circumstances exist.
A nozzle assembly for lowering onto a burning well or associated structure is seen in U.S. Pat. No. 5,146,995, issued to Hilton S. Kim on Sep. 15, 1992. A suitable fluid is discharged from the nozzle assembly for suppressing the fire. The inventor suggests that the invention be lowered into place, as from a crane or the like. This procedure would not be available in environments such as those existing in Kuwait, and may be limited to those situations in which a crane or similar apparatus preexists, and is so located as to center the apparatus over the flame. There is no suggestion in this patent of dispensing a cryogenic material from the novel apparatus, nor of remote control of release of the fire suppressing agent.
U.S. Pat. No. 4,337,831, issued to Darrel G. Thaxton on Jul. 6, 1982, illustrates apparatus for storing and releasing a fire suppressant from a plurality of storage containers. This device cooperates closely with a bell nipple of a blowout preventer of an oil well. Since maneuvering such apparatus into place on a burning well would be nearly impossible given the extreme temperatures, fast moving flame or jet of gasses, and the characteristic dark, opaque, toxic smoke released during a well fire, this apparatus is best suited for assembly prior to a fire. Again, there is no suggestion of employing a cryogenic fire suppressant, nor of remote control of the releasing of fire suppressant.
A device intended for maneuvering into position around a well pipe for subsequent fire suppression is described in U.S. Pat. No. 5,207,779, issued to Charles Chaplinski on May 4, 1993. The device is dragged horizontally from one direction into operative engagement with the well casing, rather than being airlifted, as in the present invention. More significantly, the device of Chaplinski crushes the well casing or pipe under hydraulic pressure acting as on a ram or jaw. No fire suppressing material is delivered to the fire site or is released. The use of cryogenic fire suppressant is not suggested in this patent. Although operation of the device is remote, in the sense that hydraulic lines may extend therefrom to a distant control station or source of pressure, control is limited by the reach of these lines, and is dependent upon the lines remaining in good condition. Kinking, crushing, twisting, and other distortions of the lines would defeat successful operation of the device.
A snuffing device is seen in U.S. Pat. No. 4,433,733, issued to Byron H. Cunningham on Feb. 28, 1984. The snuffer is lowered into place over the burning well or oil tank. No fire suppressing agent is released. The same difficulties in lowering the device effectively over the burning structure as set forth in the above discussion of Thaxton would occur in employing the device of Cunningham. There is no remotely operated device.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.